The two have been dating for more than five years, when Williams was working as a schoolteacher in New York. The actor used to teach high school and middle school before his breakthrough role in 2008's The Sisterhood of the Traveling Pants 2. He has played surgeon Jackson Avery on Grey's for the last three seasons.

Grey's Anatomy returns with new episodes on Thursday, Sept. 27 at 9/8c on ABC.